Title : THE INEFFICIENCY OF TRIPLET ENERGY TRANSFER FROM KETONES TO TRIVALENT RARE EARTH IONS.

Descriptive Note : Annual technical rept. no. 2, 1 Aug 67-31 May 68,

Corporate Author : MICHIGAN STATE UNIV EAST LANSING DEPT OF CHEMISTRY

Personal Author(s) : Wagner,Peter J. ; Schott,Herbert N.

Report Date : 21 JUN 1968

Pagination or Media Count : 7

Abstract : It is shown that trivalent samarium, europium, terbium, dysprosium, and erbium chlorides are only 1-2% as effective as conjugated dienes at quenching the triplet state photoelimination of para-methoxyvalerophenone and the triplet state photoreduction of benzophenone. Maximum rate constants for energy transfer from the triplet excited ketones to the rare earth ions is (10 to the 8th power)/M/sec in solvents such as methanol and aqueous acetic acid. This conclusion refutes the former common assumption that such energy transfer was diffusion-controlled. It is postulated that the tight solvation of the metal ions prevents effective overlap of donor and ionic orbitals and thus decreases the exchange interaction necessary for energy transfer. (Author)